OK I so I just purchased this van about a month ago 1995 E150 with the 5.8 liter engine, it has 167K miles on it and it runs pretty good with a few exceptions. The van always starts and runs properly, no overheat, no stalls etc... However, sometimes when I start the van after driving to the store or just down the road it will start with a very rough idle for about 3 seconds and if I don't give it just a little gas it will die. Then it will generally start right up with no issue at all. The only other similar symptom I can find is that the van really doesn't like when you floor it for any reason.. I can't explain what happens aside from it just runs rough and seems to not want to accept all the fuel I'm feeding it. I have every intention of getting new plugs, wires, cap, rotor etc... Just curious if anyone has had this issue so I know where to start ... no codes, no CEL, runs fine up to 80-90 MPH (maybe more) with no issues, gas mileage is acceptable 15 MPG around town and 18-20MPG on the HWY. So if anyone has any advice, wisdom et al I would appreciate it.

 

The old 5.8s were a good workhorse and provided good reliability when maintained.
If you don't know the maintenance history, you might plan on replacing the things you mentioned along with the water pump and fuel filter.
They did perform better with Motorcraft plugs,however.
Had a fleet with more than 70 of them, and as far as I was concerned they performed very well for vehicles that ran 7 days a week and put on quite a few miles.
The emission controls were regular maintenance items , but they all stayed "stock" and always used OEM parts , some rebuilt and some new , but all from a dealership and "never" had any problems with questionable parts. After market exhaust parts were easier to install, but didn't last as long as OEM.which were heavier material. Since I didn't need any extra work, you can see why I stuck with OEM parts, it pays !
Also, keep a close eye on the front brake pads, there were no squealers to warn you pads needed replacement.

 

I would not change out any parts that are not listed as a maintenance part in the manual or failed in one way or another, you including the water pump. Those OEM parts that are still working are better in quality than the Chinese junk you will get as a replacement.Diagnose and prove that a part has failed. Guessing gets expensive! Check fuel pressure.Should be 30-45 psi. You could use a heat gun and some canned circuit cooler on the electronic ignition parts to try to duplicate the problem in the driveway..This is a long shot. Are you losing any coolant? I had a Ford with the same exact symptom. It was the head gasket with just a minor coolant leak into one of the cylinders. It temporarily fouled the plug upon start up but quickly cleaned up and ran good after a few seconds.If you are losing any amount of coolant without an external leak, it's worth investigating.

 

Might be a good idea as part of your investigation before starting the engine to include removing all the plugs and looking for any wetness, either coolant or fuel. Might help narrow it down some.

 

Very true. On my '85, I changed window motors at least 8 times in12 years. And it took 3 fuel pumps to get one that would work. No Ford parts were available.